OKLAHOMA CITY -- Energy tycoon Aubrey McClendon earned a reputation as a pioneer, backing new drilling technology, building Chesapeake Energy into one of the nation's largest independent producers of natural gas and accumulating a fortune that helped him buy part of an NBA team.

But McClendon also drew the scrutiny of federal investigators, who announced antitrust charges against him on Tuesday. Sixteen hours later, McClendon, 56, was dead in a fiery single-car traffic accident on an isolated road in northeast Oklahoma City.

"He pretty much drove straight into the wall. ... There was plenty of opportunity for him to correct and get back on the roadway and that didn't occur," Oklahoma City Police Capt. Paco Balderrama said.

Balderrama said McClendon was speeding and not wearing a seat belt in his 2013 Chevrolet Tahoe, but it's too early to tell if the collision was intentional.

McClendon, who co-founded Chesapeake Energy and served as its CEO before stepping down in 2013, was accused Tuesday of orchestrating a scheme between two large energy companies, which were not named in an indictment, from December 2007 to March 2012. The companies would decide ahead of time who would win bids, with the winner then allocating an interest in the leases to the other company, according to a statement from the Department of Justice.

In a statement released just hours before his death, McClendon fiercely denied the allegations and vowed a fight to clear his name.

"Anyone who knows me, my business record and the industry in which I have worked for 35 years, knows that I could not be guilty of violating any antitrust laws," McClendon said in the statement. "All my life I have worked to create jobs in Oklahoma, grow its economy, and to provide abundant and affordable energy to all Americans."

McClendon, part owner of the Oklahoma City Thunder, was renowned for his aggression and skill in acquiring oil and gas drilling rights. As drillers learned to unlock natural gas from shale formations using hydraulic fracturing over the last decade, McClendon pushed the company to acquire enormous tracts of land in several states.

"We've completely transformed the natural gas industry, and I wouldn't be surprised if we transform the oil business in the next few years too," McClendon told the AP in a 2011 interview.

The strategy landed the company promising assets, boosted its own production and helped fuel the national boom in natural gas production. Chesapeake's 20-acre campus sprawls through an exclusive area of Oklahoma City, its Georgian-style brick buildings surrounded by manicured lawns and sycamore and elm trees.

But the acquisitions also saddled the company enormous debt, and Chesapeake eventually became victim of its own success. Natural gas prices plummeted along with all the new drilling, reducing revenues for the company and making the debt harder to repay.

McClendon left Chesapeake in January 2013 amid philosophical differences with a new board of directors, and founded American Energy Partners, where he was chairman and CEO.

"Aubrey's tremendous leadership, vision, and passion for the energy industry had an impact on the community, the country, and the world," AEP said in a statement. "We are tremendously proud of his legacy and will continue to work hard to live up to the unmatched standards he set for excellence and integrity."

McClendon could frequently be spotted in his courtside seats near the Thunder bench in the arena named after the company he founded in 1989 with his friend, Tom Ward, with an initial $50,000 investment.

Thunder head coach Billy Donovan said he addressed the team after learning of McClendon's death.

"He always treated me very, very well," Donovan said. "He was a very generous guy, and I'm just really saddened by what happened today."

Fellow energy magnate and Oklahoma native T. Boone Pickens described McClendon as a "major player in leading the stunning energy renaissance in America."

"He was charismatic and a true American entrepreneur," Pickens said in a statement. "No individual is without flaws, but his impact on American energy will be long-lasting."